The overall goal of this research proposal is to design, engineer, and test in vivo a type I collagen-based endovascular template for the therapy of cerebral aneurysms. Cerebral aneurysms are present in at least 0.5-1.0% of the United States population, and aneurysm rupture remains an important cause of morbidity and mortality. Even in major referral centers, a significant number of aneurysms are not amenable to surgical repair. The device described in this proposal is specifically designed to act as a vascular template to support and guide vascular regeneration at the base of the aneurysm and to inhibit blood flow into the aneurysm sac, resulting in thrombosis of the aneurysm. A preliminary in vitro study was performed using the initial prototype developed by the principle investigator of this proposal. The results demonstrated that type I collagen may be used to construct a hemocompatible tubular template that produces a modest reduction in arterial luminal dimension and little change in flow. During phase I, we will examine the in vivo feasibility of the collagen template in a rabbit model, while in phase II we will extend the period of study in the rabbit model to evaluate the long term effects of the collagen template. The neurosurgical and interventional neuroradiology community is in serious need of a viable therapy for wide-neck aneurysms. If an acceptable template is developed, it is estimated that the yearly gross revenues from such a template would exceed at least $100 million. Furthermore, the work described in this proposal could be expanded to apply to a wide range of clinical applications, including percutaneous angioplasty, closure of arteriovenous fistulae, and billary, renal and esophageal procedures. If widely applied clinically, a collagen-based template could generate well over $1 billion per year worldwide. PROPOSED COMMERCIAL APPLICATIONS: See above abstract